NETCONF Working Group K. Watsen Internet-Draft Watsen Networks Intended status: Standards Track G. Wu Expires: 9 January 2021 Cisco Systems 8 July 2020 YANG Groupings for TLS Clients and TLS Servers draft-ietf-netconf-tls-client-server-20 Abstract This document defines three YANG modules: the first defines groupings for a generic TLS client, the second defines groupings for a generic TLS server, and the third defines common identities and groupings used by both the client and the server. It is intended that these groupings will be used by applications using the TLS protocol. Editorial Note (To be removed by RFC Editor) This draft contains placeholder values that need to be replaced with finalized values at the time of publication. This note summarizes all of the substitutions that are needed. No other RFC Editor instructions are specified elsewhere in this document. Artwork in this document contains shorthand references to drafts in progress. Please apply the following replacements: * "AAAA" --> the assigned RFC value for draft-ietf-netconf-crypto- types * "BBBB" --> the assigned RFC value for draft-ietf-netconf-trust- anchors * "CCCC" --> the assigned RFC value for draft-ietf-netconf-keystore * "DDDD" --> the assigned RFC value for draft-ietf-netconf-tcp- client-server * "FFFF" --> the assigned RFC value for this draft Artwork in this document contains placeholder values for the date of publication of this draft. Please apply the following replacement: * "2020-07-08" --> the publication date of this draft The following Appendix section is to be removed prior to publication: Watsen & Wu Expires 9 January 2021 [Page 1] Internet-Draft Groupings for TLS Clients and Servers July 2020 * Appendix A. Change Log Status of This Memo This Internet-Draft is submitted in full conformance with the provisions of BCP 78 and BCP 79. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF). Note that other groups may also distribute working documents as Internet-Drafts. The list of current Internet- Drafts is at https://datatracker.ietf.org/drafts/current/. Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress." This Internet-Draft will expire on 9 January 2021. Copyright Notice Copyright (c) 2020 IETF Trust and the persons identified as the document authors. All rights reserved. This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents (https://trustee.ietf.org/ license-info) in effect on the date of publication of this document. Please review these documents carefully, as they describe your rights and restrictions with respect to this document. Code Components extracted from this document must include Simplified BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Simplified BSD License. Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3 1.1. Relation to other RFCs . . . . . . . . . . . . . . . . . 4 1.2. Specification Language . . . . . . . . . . . . . . . . . 6 1.3. Adherence to the NMDA . . . . . . . . . . . . . . . . . . 6 2. The "ietf-tls-common" Module . . . . . . . . . . . . . . . . 6 2.1. Data Model Overview . . . . . . . . . . . . . . . . . . . 7 2.2. Example Usage . . . . . . . . . . . . . . . . . . . . . . 9 2.3. YANG Module . . . . . . . . . . . . . . . . . . . . . . . 10 3. The "ietf-tls-client" Module . . . . . . . . . . . . . . . . 19 3.1. Data Model Overview . . . . . . . . . . . . . . . . . . . 19 3.2. Example Usage . . . . . . . . . . . . . . . . . . . . . . 21 3.3. YANG Module . . . . . . . . . . . . . . . . . . . . . . . 24 4. The "ietf-tls-server" Module . . . . . . . . . . . . . . . . 32 Watsen & Wu Expires 9 January 2021 [Page 2] Internet-Draft Groupings for TLS Clients and Servers July 2020 4.1. Data Model Overview . . . . . . . . . . . . . . . . . . . 32 4.2. Example Usage . . . . . . . . . . . . . . . . . . . . . . 34 4.3. YANG Module . . . . . . . . . . . . . . . . . . . . . . . 38 5. Security Considerations . . . . . . . . . . . . . . . . . . . 45 5.1. The "ietf-tls-common" YANG Module . . . . . . . . . . . . 45 5.2. The "ietf-tls-client" YANG Module . . . . . . . . . . . . 46 5.3. The "ietf-tls-server" YANG Module . . . . . . . . . . . . 47 6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 48 6.1. The IETF XML Registry . . . . . . . . . . . . . . . . . . 48 6.2. The YANG Module Names Registry . . . . . . . . . . . . . 48 7. References . . . . . . . . . . . . . . . . . . . . . . . . . 48 7.1. Normative References . . . . . . . . . . . . . . . . . . 48 7.2. Informative References . . . . . . . . . . . . . . . . . 50 Appendix A. Change Log . . . . . . . . . . . . . . . . . . . . . 52 A.1. 00 to 01 . . . . . . . . . . . . . . . . . . . . . . . . 52 A.2. 01 to 02 . . . . . . . . . . . . . . . . . . . . . . . . 52 A.3. 02 to 03 . . . . . . . . . . . . . . . . . . . . . . . . 52 A.4. 03 to 04 . . . . . . . . . . . . . . . . . . . . . . . . 52 A.5. 04 to 05 . . . . . . . . . . . . . . . . . . . . . . . . 53 A.6. 05 to 06 . . . . . . . . . . . . . . . . . . . . . . . . 53 A.7. 06 to 07 . . . . . . . . . . . . . . . . . . . . . . . . 53 A.8. 07 to 08 . . . . . . . . . . . . . . . . . . . . . . . . 53 A.9. 08 to 09 . . . . . . . . . . . . . . . . . . . . . . . . 53 A.10. 09 to 10 . . . . . . . . . . . . . . . . . . . . . . . . 54 A.11. 10 to 11 . . . . . . . . . . . . . . . . . . . . . . . . 54 A.12. 11 to 12 . . . . . . . . . . . . . . . . . . . . . . . . 54 A.13. 12 to 13 . . . . . . . . . . . . . . . . . . . . . . . . 54 A.14. 12 to 13 . . . . . . . . . . . . . . . . . . . . . . . . 55 A.15. 13 to 14 . . . . . . . . . . . . . . . . . . . . . . . . 55 A.16. 14 to 15 . . . . . . . . . . . . . . . . . . . . . . . . 55 A.17. 15 to 16 . . . . . . . . . . . . . . . . . . . . . . . . 55 A.18. 16 to 17 . . . . . . . . . . . . . . . . . . . . . . . . 55 A.19. 17 to 18 . . . . . . . . . . . . . . . . . . . . . . . . 56 A.20. 18 to 19 . . . . . . . . . . . . . . . . . . . . . . . . 56 A.21. 19 to 20 . . . . . . . . . . . . . . . . . . . . . . . . 56 Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . . 57 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 57 1. Introduction This document defines three YANG 1.1 [RFC7950] modules: the first defines a grouping for a generic TLS client, the second defines a grouping for a generic TLS server, and the third defines identities and groupings common to both the client and the server (TLS is defined in [RFC5246]). It is intended that these groupings will be used by applications using the TLS protocol. For instance, these groupings could be used to help define the data model for an HTTPS [RFC2818] server or a NETCONF over TLS [RFC7589] based server. Watsen & Wu Expires 9 January 2021 [Page 3] Internet-Draft Groupings for TLS Clients and Servers July 2020 The client and server YANG modules in this document each define one grouping, which is focused on just TLS-specific configuration, and specifically avoids any transport-level configuration, such as what ports to listen-on or connect-to. This affords applications the opportunity to define their own strategy for how the underlying TCP connection is established. For instance, applications supporting NETCONF Call Home [RFC8071] could use the "ssh-server-grouping" grouping for the TLS parts it provides, while adding data nodes for the TCP-level call-home configuration. 1.1. Relation to other RFCs This document presents one or more YANG modules [RFC7950] that are part of a collection of RFCs that work together to define configuration modules for clients and servers of both the NETCONF [RFC6241] and RESTCONF [RFC8040] protocols. The modules have been defined in a modular fashion to enable their use by other efforts, some of which are known to be in progress at the time of this writing, with many more expected to be defined in time. The relationship between the various RFCs in the collection is presented in the below diagram. The labels in the diagram represent the primary purpose provided by each RFC. Links the each RFC are provided below the diagram. Watsen & Wu Expires 9 January 2021 [Page 4] Internet-Draft Groupings for TLS Clients and Servers July 2020 crypto-types ^ ^ / \ / \ truststore keystore ^ ^ ^ ^ | +---------+ | | | | | | | +------------+ | tcp-client-server | / | | ^ ^ ssh-client-server | | | | ^ tls-client-server | | | ^ ^ http-client-server | | | | | ^ | | | +-----+ +---------+ | | | | | | | | +-----------|--------|--------------+ | | | | | | | | +-----------+ | | | | | | | | | | | | | | | | | netconf-client-server restconf-client-server +=======================+===========================================+ | Label in Diagram | Originating RFC | +=======================+===========================================+ | crypto-types | [I-D.ietf-netconf-crypto-types] | +-----------------------+-------------------------------------------+ | truststore | [I-D.ietf-netconf-trust-anchors] | +-----------------------+-------------------------------------------+ | keystore | [I-D.ietf-netconf-keystore] | +-----------------------+-------------------------------------------+ | tcp-client-server | [I-D.ietf-netconf-tcp-client-server] | +-----------------------+-------------------------------------------+ | ssh-client-server | [I-D.ietf-netconf-ssh-client-server] | +-----------------------+-------------------------------------------+ | tls-client-server | [I-D.ietf-netconf-tls-client-server] | +-----------------------+-------------------------------------------+ | http-client-server | [I-D.ietf-netconf-http-client-server] | +-----------------------+-------------------------------------------+ | netconf-client-server | [I-D.ietf-netconf-netconf-client-server] | +-----------------------+-------------------------------------------+ |restconf-client-server | [I-D.ietf-netconf-restconf-client-server] | +-----------------------+-------------------------------------------+ Table 1: Label to RFC Mapping Watsen & Wu Expires 9 January 2021 [Page 5] Internet-Draft Groupings for TLS Clients and Servers July 2020 1.2. Specification Language The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in BCP 14 [RFC2119] [RFC8174] when, and only when, they appear in all capitals, as shown here. 1.3. Adherence to the NMDA This document in compliant with the Network Management Datastore Architecture (NMDA) [RFC8342]. For instance, as described in [I-D.ietf-netconf-trust-anchors] and [I-D.ietf-netconf-keystore], trust anchors and keys installed during manufacturing are expected to appear in . 2. The "ietf-tls-common" Module The TLS common model presented in this section contains identities and groupings common to both TLS clients and TLS servers. The "hello-params-grouping" grouping can be used to configure the list of TLS algorithms permitted by the TLS client or TLS server. The lists of algorithms are ordered such that, if multiple algorithms are permitted by the client, the algorithm that appears first in its list that is also permitted by the server is used for the TLS transport layer connection. The ability to restrict the algorithms allowed is provided in this grouping for TLS clients and TLS servers that are capable of doing so and may serve to make TLS clients and TLS servers compliant with local security policies. This model supports both TLS1.2 [RFC5246] and TLS 1.3 [RFC8446]. TLS 1.2 and TLS 1.3 have different ways defining their own supported cryptographic algorithms, see TLS and DTLS IANA registries page (https://www.iana.org/assignments/tls-parameters/tls- parameters.xhtml): Watsen & Wu Expires 9 January 2021 [Page 6] Internet-Draft Groupings for TLS Clients and Servers July 2020 * TLS 1.2 defines four categories of registries for cryptographic algorithms: TLS Cipher Suites, TLS SignatureAlgorithm, TLS HashAlgorithm, TLS Supported Groups. TLS Cipher Suites plays the role of combining all of them into one set, as each value of the set represents a unique and feasible combination of all the cryptographic algorithms, and thus the other three registry categories do not need to be considered here. In this document, the TLS common model only chooses those TLS1.2 algorithms in TLS Cipher Suites which are marked as recommended: TLS_DHE_RSA_WITH_AES_128_GCM_SHA256, TLS_DHE_RSA_WITH_AES_256_GCM_SHA384, TLS_DHE_PSK_WITH_AES_128_GCM_SHA256, TLS_DHE_PSK_WITH_AES_256_GCM_SHA384, and so on. All chosen algorithms are enumerated in Table 1-1 below; * TLS 1.3 defines its supported algorithms differently. Firstly, it defines three categories of registries for cryptographic algorithms: TLS Cipher Suites, TLS SignatureScheme, TLS Supported Groups. Secondly, all three of these categories are useful, since they represent different parts of all the supported algorithms respectively. Thus, all of these registries categories are considered here. In this draft, the TLS common model chooses only those TLS1.3 algorithms specified in B.4, 4.2.3, 4.2.7 of [RFC8446]. Thus, in order to support both TLS1.2 and TLS1.3, the cipher-suites part of the "hello-params-grouping" grouping should include three parameters for configuring its permitted TLS algorithms, which are: TLS Cipher Suites, TLS SignatureScheme, TLS Supported Groups. Note that TLS1.2 only uses TLS Cipher Suites. Features are defined for algorithms that are OPTIONAL or are not widely supported by popular implementations. Note that the list of algorithms is not exhaustive. 2.1. Data Model Overview 2.1.1. Features The following diagram lists all the "feature" statements defined in the "ietf-tls-common" module: Watsen & Wu Expires 9 January 2021 [Page 7] Internet-Draft Groupings for TLS Clients and Servers July 2020 Features: +-- tls-1_0 +-- tls-1_1 +-- tls-1_2 +-- tls-1_3 +-- tls-ecc +-- tls-dhe +-- tls-3des +-- tls-gcm +-- tls-sha2 2.1.2. Identities The following diagram illustrates the relationship amongst the "identity" statements defined in the "ietf-tls-common" module: Identities: +-- tls-version-base | +-- tls-1.0 | +-- tls-1.1 | +-- tls-1.2 +-- cipher-suite-base +-- rsa-with-aes-128-cbc-sha +-- rsa-with-aes-256-cbc-sha +-- rsa-with-aes-128-cbc-sha256 +-- rsa-with-aes-256-cbc-sha256 +-- dhe-rsa-with-aes-128-cbc-sha +-- dhe-rsa-with-aes-256-cbc-sha +-- dhe-rsa-with-aes-128-cbc-sha256 +-- dhe-rsa-with-aes-256-cbc-sha256 +-- ecdhe-ecdsa-with-aes-128-cbc-sha256 +-- ecdhe-ecdsa-with-aes-256-cbc-sha384 +-- ecdhe-rsa-with-aes-128-cbc-sha256 +-- ecdhe-rsa-with-aes-256-cbc-sha384 +-- ecdhe-ecdsa-with-aes-128-gcm-sha256 +-- ecdhe-ecdsa-with-aes-256-gcm-sha384 +-- ecdhe-rsa-with-aes-128-gcm-sha256 +-- ecdhe-rsa-with-aes-256-gcm-sha384 +-- rsa-with-3des-ede-cbc-sha +-- ecdhe-rsa-with-3des-ede-cbc-sha +-- ecdhe-rsa-with-aes-128-cbc-sha +-- ecdhe-rsa-with-aes-256-cbc-sha Comments: * The diagram shows that there are two base identities. * One base identity is used to specific TLS versions, while the other is used to specify cipher-suites. Watsen & Wu Expires 9 January 2021 [Page 8] Internet-Draft Groupings for TLS Clients and Servers July 2020 * These base identities are "abstract", in the object orientied programming sense, in that they only define a "class" of things, rather than a specific thing. 2.1.3. Groupings The following diagram lists all the "grouping" statements defined in the "ietf-tls-common" module: Groupings: +-- hello-params-grouping Each of these groupings are presented in the following subsections. 2.1.3.1. The "hello-params-grouping" Grouping The following tree diagram [RFC8340] illustrates the "hello-params- grouping" grouping: grouping hello-params-grouping +-- tls-versions | +-- tls-version* identityref +-- cipher-suites +-- cipher-suite* identityref Comments: * This grouping is used by both the "tls-client-grouping" and the "tls-server-grouping" groupings defined in Section 3.1.2.1 and Section 4.1.2.1, respectively. * This grouping enables client and server configurations to specify the TLS versions and cipher suites that are to be used when establishing TLS sessions. * The "cipher-suites" list is "ordered-by user". 2.1.4. Protocol-accessible Nodes The "ietf-tls-common" module does not contain any protocol-accessible nodes, but the module needs to be "implemented", as described in Section 5.6.5 of [RFC7950], in order for the identities in Section 2.1.2 to be defined. 2.2. Example Usage This section shows how it would appear if the "hello-params-grouping" grouping were populated with some data. Watsen & Wu Expires 9 January 2021 [Page 9] Internet-Draft Groupings for TLS Clients and Servers July 2020 tlscmn:tls-1.1 tlscmn:tls-1.2 tlscmn:dhe-rsa-with-aes-128-cbc-sha tlscmn:rsa-with-aes-128-cbc-sha tlscmn:rsa-with-3des-ede-cbc-sha 2.3. YANG Module This YANG module has a normative references to [RFC4346], [RFC5246], [RFC5288], [RFC5289], and [RFC8422]. This YANG module has a informative references to [RFC2246], [RFC4346], [RFC5246], and [RFC8446]. file "ietf-tls-common@2020-07-08.yang" module ietf-tls-common { yang-version 1.1; namespace "urn:ietf:params:xml:ns:yang:ietf-tls-common"; prefix tlscmn; organization "IETF NETCONF (Network Configuration) Working Group"; contact "WG Web: WG List: Author: Kent Watsen Author: Gary Wu "; description "This module defines a common features, identities, and groupings for Transport Layer Security (TLS). Copyright (c) 2020 IETF Trust and the persons identified as authors of the code. All rights reserved. Redistribution and use in source and binary forms, with or without modification, is permitted pursuant to, and subject to the license terms contained in, the Simplified Watsen & Wu Expires 9 January 2021 [Page 10] Internet-Draft Groupings for TLS Clients and Servers July 2020 BSD License set forth in Section 4.c of the IETF Trust's Legal Provisions Relating to IETF Documents (https://trustee.ietf.org/license-info). This version of this YANG module is part of RFC XXXX (https://www.rfc-editor.org/info/rfcXXXX); see the RFC itself for full legal notices. The key words 'MUST', 'MUST NOT', 'REQUIRED', 'SHALL', 'SHALL NOT', 'SHOULD', 'SHOULD NOT', 'RECOMMENDED', 'NOT RECOMMENDED', 'MAY', and 'OPTIONAL' in this document are to be interpreted as described in BCP 14 (RFC 2119) (RFC 8174) when, and only when, they appear in all capitals, as shown here."; revision 2020-07-08 { description "Initial version"; reference "RFC XXXX: YANG Groupings for TLS Clients and TLS Servers"; } // Features feature tls-1_0 { description "TLS Protocol Version 1.0 is supported."; reference "RFC 2246: The TLS Protocol Version 1.0"; } feature tls-1_1 { description "TLS Protocol Version 1.1 is supported."; reference "RFC 4346: The Transport Layer Security (TLS) Protocol Version 1.1"; } feature tls-1_2 { description "TLS Protocol Version 1.2 is supported."; reference "RFC 5246: The Transport Layer Security (TLS) Protocol Version 1.2"; } feature tls-1_3 { Watsen & Wu Expires 9 January 2021 [Page 11] Internet-Draft Groupings for TLS Clients and Servers July 2020 description "TLS Protocol Version 1.2 is supported."; reference "RFC 8446: The Transport Layer Security (TLS) Protocol Version 1.3"; } feature tls-ecc { description "Elliptic Curve Cryptography (ECC) is supported for TLS."; reference "RFC 8422: Elliptic Curve Cryptography (ECC) Cipher Suites for Transport Layer Security (TLS)"; } feature tls-dhe { description "Ephemeral Diffie-Hellman key exchange is supported for TLS."; reference "RFC 5246: The Transport Layer Security (TLS) Protocol Version 1.2"; } feature tls-3des { description "The Triple-DES block cipher is supported for TLS."; reference "RFC 5246: The Transport Layer Security (TLS) Protocol Version 1.2"; } feature tls-gcm { description "The Galois/Counter Mode authenticated encryption mode is supported for TLS."; reference "RFC 5288: AES Galois Counter Mode (GCM) Cipher Suites for TLS"; } feature tls-sha2 { description "The SHA2 family of cryptographic hash functions is supported for TLS."; reference "FIPS PUB 180-4: Secure Hash Standard (SHS)"; } Watsen & Wu Expires 9 January 2021 [Page 12] Internet-Draft Groupings for TLS Clients and Servers July 2020 // Identities identity tls-version-base { description "Base identity used to identify TLS protocol versions."; } identity tls-1.0 { if-feature "tls-1_0"; base tls-version-base; description "TLS Protocol Version 1.0."; reference "RFC 2246: The TLS Protocol Version 1.0"; } identity tls-1.1 { if-feature "tls-1_1"; base tls-version-base; description "TLS Protocol Version 1.1."; reference "RFC 4346: The Transport Layer Security (TLS) Protocol Version 1.1"; } identity tls-1.2 { if-feature "tls-1_2"; base tls-version-base; description "TLS Protocol Version 1.2."; reference "RFC 5246: The Transport Layer Security (TLS) Protocol Version 1.2"; } identity cipher-suite-base { description "Base identity used to identify TLS cipher suites."; } identity rsa-with-aes-128-cbc-sha { base cipher-suite-base; description "Cipher suite TLS_RSA_WITH_AES_128_CBC_SHA."; reference "RFC 5246: The Transport Layer Security (TLS) Protocol Version 1.2"; Watsen & Wu Expires 9 January 2021 [Page 13] Internet-Draft Groupings for TLS Clients and Servers July 2020 } identity rsa-with-aes-256-cbc-sha { base cipher-suite-base; description "Cipher suite TLS_RSA_WITH_AES_256_CBC_SHA."; reference "RFC 5246: The Transport Layer Security (TLS) Protocol Version 1.2"; } identity rsa-with-aes-128-cbc-sha256 { if-feature "tls-sha2"; base cipher-suite-base; description "Cipher suite TLS_RSA_WITH_AES_128_CBC_SHA256."; reference "RFC 5246: The Transport Layer Security (TLS) Protocol Version 1.2"; } identity rsa-with-aes-256-cbc-sha256 { if-feature "tls-sha2"; base cipher-suite-base; description "Cipher suite TLS_RSA_WITH_AES_256_CBC_SHA256."; reference "RFC 5246: The Transport Layer Security (TLS) Protocol Version 1.2"; } identity dhe-rsa-with-aes-128-cbc-sha { if-feature "tls-dhe"; base cipher-suite-base; description "Cipher suite TLS_DHE_RSA_WITH_AES_128_CBC_SHA."; reference "RFC 5246: The Transport Layer Security (TLS) Protocol Version 1.2"; } identity dhe-rsa-with-aes-256-cbc-sha { if-feature "tls-dhe"; base cipher-suite-base; description "Cipher suite TLS_DHE_RSA_WITH_AES_256_CBC_SHA."; reference "RFC 5246: The Transport Layer Security (TLS) Protocol Watsen & Wu Expires 9 January 2021 [Page 14] Internet-Draft Groupings for TLS Clients and Servers July 2020 Version 1.2"; } identity dhe-rsa-with-aes-128-cbc-sha256 { if-feature "tls-dhe and tls-sha2"; base cipher-suite-base; description "Cipher suite TLS_DHE_RSA_WITH_AES_128_CBC_SHA256."; reference "RFC 5246: The Transport Layer Security (TLS) Protocol Version 1.2"; } identity dhe-rsa-with-aes-256-cbc-sha256 { if-feature "tls-dhe and tls-sha2"; base cipher-suite-base; description "Cipher suite TLS_DHE_RSA_WITH_AES_256_CBC_SHA256."; reference "RFC 5246: The Transport Layer Security (TLS) Protocol Version 1.2"; } identity ecdhe-ecdsa-with-aes-128-cbc-sha256 { if-feature "tls-ecc and tls-sha2"; base cipher-suite-base; description "Cipher suite TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256."; reference "RFC 5289: TLS Elliptic Curve Cipher Suites with SHA-256/384 and AES Galois Counter Mode (GCM)"; } identity ecdhe-ecdsa-with-aes-256-cbc-sha384 { if-feature "tls-ecc and tls-sha2"; base cipher-suite-base; description "Cipher suite TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA384."; reference "RFC 5289: TLS Elliptic Curve Cipher Suites with SHA-256/384 and AES Galois Counter Mode (GCM)"; } identity ecdhe-rsa-with-aes-128-cbc-sha256 { if-feature "tls-ecc and tls-sha2"; base cipher-suite-base; description "Cipher suite TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256."; Watsen & Wu Expires 9 January 2021 [Page 15] Internet-Draft Groupings for TLS Clients and Servers July 2020 reference "RFC 5289: TLS Elliptic Curve Cipher Suites with SHA-256/384 and AES Galois Counter Mode (GCM)"; } identity ecdhe-rsa-with-aes-256-cbc-sha384 { if-feature "tls-ecc and tls-sha2"; base cipher-suite-base; description "Cipher suite TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384."; reference "RFC 5289: TLS Elliptic Curve Cipher Suites with SHA-256/384 and AES Galois Counter Mode (GCM)"; } identity ecdhe-ecdsa-with-aes-128-gcm-sha256 { if-feature "tls-ecc and tls-gcm and tls-sha2"; base cipher-suite-base; description "Cipher suite TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256."; reference "RFC 5289: TLS Elliptic Curve Cipher Suites with SHA-256/384 and AES Galois Counter Mode (GCM)"; } identity ecdhe-ecdsa-with-aes-256-gcm-sha384 { if-feature "tls-ecc and tls-gcm and tls-sha2"; base cipher-suite-base; description "Cipher suite TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384."; reference "RFC 5289: TLS Elliptic Curve Cipher Suites with SHA-256/384 and AES Galois Counter Mode (GCM)"; } identity ecdhe-rsa-with-aes-128-gcm-sha256 { if-feature "tls-ecc and tls-gcm and tls-sha2"; base cipher-suite-base; description "Cipher suite TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256."; reference "RFC 5289: TLS Elliptic Curve Cipher Suites with SHA-256/384 and AES Galois Counter Mode (GCM)"; } identity ecdhe-rsa-with-aes-256-gcm-sha384 { if-feature "tls-ecc and tls-gcm and tls-sha2"; base cipher-suite-base; Watsen & Wu Expires 9 January 2021 [Page 16] Internet-Draft Groupings for TLS Clients and Servers July 2020 description "Cipher suite TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384."; reference "RFC 5289: TLS Elliptic Curve Cipher Suites with SHA-256/384 and AES Galois Counter Mode (GCM)"; } identity rsa-with-3des-ede-cbc-sha { if-feature "tls-3des"; base cipher-suite-base; description "Cipher suite TLS_RSA_WITH_3DES_EDE_CBC_SHA."; reference "RFC 5246: The Transport Layer Security (TLS) Protocol Version 1.2"; } identity ecdhe-rsa-with-3des-ede-cbc-sha { if-feature "tls-ecc and tls-3des"; base cipher-suite-base; description "Cipher suite TLS_ECDHE_RSA_WITH_3DES_EDE_CBC_SHA."; reference "RFC 8422: Elliptic Curve Cryptography (ECC) Cipher Suites for Transport Layer Security (TLS)"; } identity ecdhe-rsa-with-aes-128-cbc-sha { if-feature "tls-ecc"; base cipher-suite-base; description "Cipher suite TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA."; reference "RFC 8422: Elliptic Curve Cryptography (ECC) Cipher Suites for Transport Layer Security (TLS)"; } identity ecdhe-rsa-with-aes-256-cbc-sha { if-feature "tls-ecc"; base cipher-suite-base; description "Cipher suite TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA."; reference "RFC 8422: Elliptic Curve Cryptography (ECC) Cipher Suites for Transport Layer Security (TLS)"; } // Groupings Watsen & Wu Expires 9 January 2021 [Page 17] Internet-Draft Groupings for TLS Clients and Servers July 2020 grouping hello-params-grouping { description "A reusable grouping for TLS hello message parameters."; reference "RFC 5246: The Transport Layer Security (TLS) Protocol Version 1.2"; container tls-versions { description "Parameters regarding TLS versions."; leaf-list tls-version { type identityref { base tls-version-base; } description "Acceptable TLS protocol versions. If this leaf-list is not configured (has zero elements) the acceptable TLS protocol versions are implementation- defined."; } } container cipher-suites { description "Parameters regarding cipher suites."; leaf-list cipher-suite { type identityref { base cipher-suite-base; } ordered-by user; description "Acceptable cipher suites in order of descending preference. The configured host key algorithms should be compatible with the algorithm used by the configured private key. Please see Section 5 of RFC XXXX for valid combinations. If this leaf-list is not configured (has zero elements) the acceptable cipher suites are implementation- defined."; reference "RFC XXXX: YANG Groupings for TLS Clients and TLS Servers"; } } } } Watsen & Wu Expires 9 January 2021 [Page 18] Internet-Draft Groupings for TLS Clients and Servers July 2020 3. The "ietf-tls-client" Module 3.1. Data Model Overview 3.1.1. Features The following diagram lists all the "feature" statements defined in the "ietf-tls-client" module: Features: +-- tls-client-hello-params-config +-- tls-client-keepalives +-- x509-certificate-auth +-- raw-public-key-auth +-- psk-auth 3.1.2. Groupings The following diagram lists all the "grouping" statements defined in the "ietf-tls-client" module: Groupings: +-- tls-client-grouping Each of these groupings are presented in the following subsections. 3.1.2.1. The "tls-client-grouping" Grouping The following tree diagram [RFC8340] illustrates the "tls-client- grouping" grouping: Watsen & Wu Expires 9 January 2021 [Page 19] Internet-Draft Groupings for TLS Clients and Servers July 2020 =============== NOTE: '\' line wrapping per RFC 8792 ================ grouping tls-client-grouping +-- client-identity! | +-- (auth-type) | +--:(certificate) {x509-certificate-auth}? | | +-- certificate | | +---u ks:local-or-keystore-end-entity-cert-with-key-\ grouping | +--:(raw-public-key) {raw-public-key-auth}? | | +-- raw-private-key | | +---u ks:local-or-keystore-asymmetric-key-grouping | +--:(psk) {psk-auth}? | +-- psk | +---u ks:local-or-keystore-symmetric-key-grouping +-- server-authentication | +-- ca-certs! {x509-certificate-auth}? | | +---u ts:local-or-truststore-certs-grouping | +-- ee-certs! {x509-certificate-auth}? | | +---u ts:local-or-truststore-certs-grouping | +-- raw-public-keys! {raw-public-key-auth}? | | +---u ts:local-or-truststore-public-keys-grouping | +-- psks! {psk-auth}? +-- hello-params {tls-client-hello-params-config}? | +---u tlscmn:hello-params-grouping +-- keepalives {tls-client-keepalives}? +-- peer-allowed-to-send? empty +-- test-peer-aliveness! +-- max-wait? uint16 +-- max-attempts? uint8 Comments: * The "client-identity" node, which is optionally configured (as client authentication MAY occur at a higher protocol layer), configures identity credentials, each enabled by a "feature" statement defined in Section 3.1.1. * The "server-authentication" node configures trust anchors for authenticating the TLS server, with each option enabled by a "feature" statement. * The "hello-params" node , which must be enabled by a feature, configures parameters for the TLS sessions established by this configuration. Watsen & Wu Expires 9 January 2021 [Page 20] Internet-Draft Groupings for TLS Clients and Servers July 2020 * The "keepalives" node, which must be enabled by a feature, configures a "presence" container for testing the aliveness of the TLS server. The aliveness-test occurs at the TLS protocol layer. * For the referenced grouping statement(s): - The "local-or-keystore-end-entity-cert-with-key-grouping" grouping is discussed in Section 2.1.3.6 of [I-D.ietf-netconf-keystore]. - The "local-or-keystore-asymmetric-key-grouping" grouping is discussed in Section 2.1.3.4 of [I-D.ietf-netconf-keystore]. - The "local-or-keystore-symmetric-key-grouping" grouping is discussed in Section 2.1.3.3 of [I-D.ietf-netconf-keystore]. - The "local-or-truststore-certs-grouping" grouping is discussed in Section 2.1.3.1 of [I-D.ietf-netconf-trust-anchors]. - The "local-or-truststore-public-keys-grouping" grouping is discussed in Section 2.1.3.2 of [I-D.ietf-netconf-trust-anchors]. - The "hello-params-grouping" grouping is discussed in Section 2.1.3.1 in this document. 3.1.3. Protocol-accessible Nodes The "ietf-tls-client" module does not contain any protocol-accessible nodes. 3.2. Example Usage This section presents two examples showing the "tls-client-grouping" grouping populated with some data. These examples are effectively the same except the first configures the client identity using a local key while the second uses a key configured in a keystore. Both examples are consistent with the examples presented in Section 2 of [I-D.ietf-netconf-trust-anchors] and Section 3.2 of [I-D.ietf-netconf-keystore]. The following configuration example uses local-definitions for the client identity and server authentication: =============== NOTE: '\' line wrapping per RFC 8792 ================ Watsen & Wu Expires 9 January 2021 [Page 21] Internet-Draft Groupings for TLS Clients and Servers July 2020 ct:subject-public-key-info-format base64encodedvalue== ct:rsa-private-key-format base64encodedvalue== base64encodedvalue== Server Cert Issuer #1 base64encodedvalue== Server Cert Issuer #2 base64encodedvalue== My Application #1 Watsen & Wu Expires 9 January 2021 [Page 22] Internet-Draft Groupings for TLS Clients and Servers July 2020 base64encodedvalue== My Application #2 base64encodedvalue== corp-fw1 ct:subject-public-key-info-format base64encodedvalue== corp-fw1 ct:subject-public-key-info-format base64encodedvalue== 30 3 The following configuration example uses keystore-references for the client identity and truststore-references for server authentication: from the keystore: =============== NOTE: '\' line wrapping per RFC 8792 ================ Watsen & Wu Expires 9 January 2021 [Page 23] Internet-Draft Groupings for TLS Clients and Servers July 2020 rsa-asymmetric-key ex-rsa-cert trusted-server-ca-certs trusted-server-ee-certs Raw Public Keys for TLS Servers 30 3 3.3. YANG Module This YANG module has normative references to [I-D.ietf-netconf-trust-anchors] and [I-D.ietf-netconf-keystore]. file "ietf-tls-client@2020-07-08.yang" Watsen & Wu Expires 9 January 2021 [Page 24] Internet-Draft Groupings for TLS Clients and Servers July 2020 module ietf-tls-client { yang-version 1.1; namespace "urn:ietf:params:xml:ns:yang:ietf-tls-client"; prefix tlsc; import ietf-netconf-acm { prefix nacm; reference "RFC 8341: Network Configuration Access Control Model"; } import ietf-crypto-types { prefix ct; reference "RFC AAAA: YANG Data Types and Groupings for Cryptography"; } import ietf-truststore { prefix ts; reference "RFC BBBB: A YANG Data Model for a Truststore"; } import ietf-keystore { prefix ks; reference "RFC CCCC: A YANG Data Model for a Keystore"; } import ietf-tls-common { prefix tlscmn; revision-date 2020-07-08; // stable grouping definitions reference "RFC FFFF: YANG Groupings for TLS Clients and TLS Servers"; } organization "IETF NETCONF (Network Configuration) Working Group"; contact "WG Web: WG List: Author: Kent Watsen Author: Gary Wu "; description "This module defines reusable groupings for TLS clients that can be used as a basis for specific TLS client instances. Watsen & Wu Expires 9 January 2021 [Page 25] Internet-Draft Groupings for TLS Clients and Servers July 2020 Copyright (c) 2020 IETF Trust and the persons identified as authors of the code. All rights reserved. Redistribution and use in source and binary forms, with or without modification, is permitted pursuant to, and subject to the license terms contained in, the Simplified BSD License set forth in Section 4.c of the IETF Trust's Legal Provisions Relating to IETF Documents (https://trustee.ietf.org/license-info). This version of this YANG module is part of RFC FFFF (https://www.rfc-editor.org/info/rfcFFFF); see the RFC itself for full legal notices. The key words 'MUST', 'MUST NOT', 'REQUIRED', 'SHALL', 'SHALL NOT', 'SHOULD', 'SHOULD NOT', 'RECOMMENDED', 'NOT RECOMMENDED', 'MAY', and 'OPTIONAL' in this document are to be interpreted as described in BCP 14 (RFC 2119) (RFC 8174) when, and only when, they appear in all capitals, as shown here."; revision 2020-07-08 { description "Initial version"; reference "RFC FFFF: YANG Groupings for TLS Clients and TLS Servers"; } // Features feature tls-client-hello-params-config { description "TLS hello message parameters are configurable on a TLS client."; } feature tls-client-keepalives { description "Per socket TLS keepalive parameters are configurable for TLS clients on the server implementing this feature."; } feature x509-certificate-auth { description "Indicates that the client supports authenticating servers using X.509 certificates."; } Watsen & Wu Expires 9 January 2021 [Page 26] Internet-Draft Groupings for TLS Clients and Servers July 2020 feature raw-public-key-auth { description "Indicates that the client supports authenticating servers using ray public keys."; } feature psk-auth { description "Indicates that the client supports authenticating servers using PSKs (pre-shared or pairwise-symmetric keys)."; } // Groupings grouping tls-client-grouping { description "A reusable grouping for configuring a TLS client without any consideration for how an underlying TCP session is established. Note that this grouping uses fairly typical descendent node names such that a stack of 'uses' statements will have name conflicts. It is intended that the consuming data model will resolve the issue (e.g., by wrapping the 'uses' statement in a container called 'tls-client-parameters'). This model purposely does not do this itself so as to provide maximum flexibility to consuming models."; container client-identity { nacm:default-deny-write; presence "Indicates that TLS-level client authentication is sent. Present so that the 'choice' node's mandatory true doesn't imply that a client identity must be configured."; description "Identity credentials the TLS client MAY present when establishing a connection to a TLS server. If not configured, then client authentication is presumed to occur a protocol layer above TLS. When configured, and requested by the TLS server when establishing a TLS session, these credentials are passed in the Certificate message defined in Section 7.4.2 of RFC 5246."; reference Watsen & Wu Expires 9 January 2021 [Page 27] Internet-Draft Groupings for TLS Clients and Servers July 2020 "RFC 5246: The Transport Layer Security (TLS) Protocol Version 1.2 RFC CCCC: A YANG Data Model for a Keystore"; choice auth-type { mandatory true; description "A choice amongst available authentication types."; /* FIXME: delete now? Not mandatory as client identity MAY be provided by another layer in the protocol stack (e.g., an HTTP authentication mechanism).";*/ case certificate { if-feature x509-certificate-auth; container certificate { description "Specifies the client identity using a certificate."; uses ks:local-or-keystore-end-entity-cert-with-key-grouping{ refine "local-or-keystore/local/local-definition" { must 'public-key-format' + ' = "ct:subject-public-key-info-format"'; } refine "local-or-keystore/keystore/keystore-reference" + "/asymmetric-key" { must 'deref(.)/../ks:public-key-format' + ' = "ct:subject-public-key-info-format"'; } } } } case raw-public-key { if-feature raw-public-key-auth; container raw-private-key { description "Specifies the client identity using a raw private key."; uses ks:local-or-keystore-asymmetric-key-grouping { refine "local-or-keystore/local/local-definition" { must 'public-key-format' + ' = "ct:subject-public-key-info-format"'; } refine "local-or-keystore/keystore" + "/keystore-reference" { must 'deref(.)/../ks:public-key-format' + ' = "ct:subject-public-key-info-format"'; } } } Watsen & Wu Expires 9 January 2021 [Page 28] Internet-Draft Groupings for TLS Clients and Servers July 2020 } case psk { if-feature psk-auth; container psk { description "Specifies the client identity using a PSK (pre-shared or pairwise-symmetric key). Note that, when the PSK is configured as a Keystore reference, the key's 'name' node MAY be used as the PSK's ID when used by the TLS protocol."; uses ks:local-or-keystore-symmetric-key-grouping { augment "local-or-keystore/local/local-definition" { if-feature "ks:local-definitions-supported"; description "Adds an 'id' value when the PSK is used by TLS."; leaf id { type string; // FIXME: is this the right type? description "The key id used in the TLS protocol for PSKs."; } } } } } } } // container client-identity container server-authentication { nacm:default-deny-write; must 'ca-certs or ee-certs or raw-public-keys or psks'; description "Specifies how the TLS client can authenticate TLS servers. Any combination of credentials is additive and unordered. Note that no configuration is required for PSK (pre-shared or pairwise-symmetric key) based authentication as the key is necessarily the same as configured in the '../client- identity' node."; container ca-certs { if-feature "x509-certificate-auth"; presence "Indicates that the TLS client can authenticate TLS servers using configured certificate authority certificates."; description "A set of certificate authority (CA) certificates used by the TLS client to authenticate TLS server certificates. A server certificate is authenticated if it has a valid chain of trust to a configured CA certificate."; Watsen & Wu Expires 9 January 2021 [Page 29] Internet-Draft Groupings for TLS Clients and Servers July 2020 reference "RFC BBBB: A YANG Data Model for a Truststore"; uses ts:local-or-truststore-certs-grouping; } container ee-certs { // FIXME: plural too much? if-feature "x509-certificate-auth"; presence "Indicates that the TLS client can authenticate TLS servers using configured server certificates."; description "A set of server certificates (i.e., end entity certificates) used by the TLS client to authenticate certificates presented by TLS servers. A server certificate is authenticated if it is an exact match to a configured server certificate."; reference "RFC BBBB: A YANG Data Model for a Truststore"; uses ts:local-or-truststore-certs-grouping; } container raw-public-keys { if-feature "raw-public-key-auth"; presence "Indicates that the TLS client can authenticate TLS servers using configured server certificates."; description "A set of raw public keys used by the TLS client to authenticate raw public keys presented by the TLS server. A raw public key is authenticated if it is an exact match to a configured raw public key."; reference "RFC BBBB: A YANG Data Model for a Truststore"; uses ts:local-or-truststore-public-keys-grouping { refine "local-or-truststore/local/local-definition" + "/public-key" { must 'public-key-format' + ' = "ct:subject-public-key-info-format"'; } refine "local-or-truststore/truststore" + "/truststore-reference" { must 'deref(.)/../*/ts:public-key-format' + ' = "ct:subject-public-key-info-format"'; } } } container psks { if-feature "psk-auth"; presence "Indicates that the TLS client can authenticate TLS servers Watsen & Wu Expires 9 January 2021 [Page 30] Internet-Draft Groupings for TLS Clients and Servers July 2020 using a configure PSK (pre-shared or pairwise-symmetric key)."; description "No configuration is required since the PSK value is the same as PSK value configured in the 'client-identity' node."; } } // container server-authentication container hello-params { nacm:default-deny-write; if-feature "tls-client-hello-params-config"; uses tlscmn:hello-params-grouping; description "Configurable parameters for the TLS hello message."; } // container hello-params container keepalives { nacm:default-deny-write; if-feature "tls-client-keepalives"; description "Configures the keepalive policy for the TLS client."; leaf peer-allowed-to-send { type empty; description "Indicates that the remote TLS server is allowed to send HeartbeatRequest messages, as defined by RFC 6520 to this TLS client."; reference "RFC 6520: Transport Layer Security (TLS) and Datagram Transport Layer Security (DTLS) Heartbeat Extension"; } container test-peer-aliveness { presence "Indicates that the TLS client proactively tests the aliveness of the remote TLS server."; description "Configures the keep-alive policy to proactively test the aliveness of the TLS server. An unresponsive TLS server is dropped after approximately max-wait * max-attempts seconds. The TLS client MUST send HeartbeatRequest messages, as defined by RFC 6520."; reference "RFC 6520: Transport Layer Security (TLS) and Datagram Transport Layer Security (DTLS) Heartbeat Extension"; leaf max-wait { type uint16 { range "1..max"; Watsen & Wu Expires 9 January 2021 [Page 31] Internet-Draft Groupings for TLS Clients and Servers July 2020 } units "seconds"; default "30"; description "Sets the amount of time in seconds after which if no data has been received from the TLS server, a TLS-level message will be sent to test the aliveness of the TLS server."; } leaf max-attempts { type uint8; default "3"; description "Sets the maximum number of sequential keep-alive messages that can fail to obtain a response from the TLS server before assuming the TLS server is no longer alive."; } } } } // grouping tls-client-grouping } // module ietf-tls-client 4. The "ietf-tls-server" Module 4.1. Data Model Overview 4.1.1. Features The following diagram lists all the "feature" statements defined in the "ietf-tls-server" module: Features: +-- tls-server-hello-params-config +-- tls-server-keepalives +-- client-auth-config-supported +-- x509-certificate-auth +-- raw-public-key-auth +-- psk-auth 4.1.2. Groupings The following diagram lists all the "grouping" statements defined in the "ietf-tls-server" module: Watsen & Wu Expires 9 January 2021 [Page 32] Internet-Draft Groupings for TLS Clients and Servers July 2020 Groupings: +-- tls-server-grouping Each of these groupings are presented in the following subsections. 4.1.2.1. The "tls-server-grouping" Grouping The following tree diagram [RFC8340] illustrates the "tls-server- grouping" grouping: =============== NOTE: '\' line wrapping per RFC 8792 ================ grouping tls-server-grouping +-- server-identity | +-- (auth-type) | +--:(certificate) {x509-certificate-auth}? | | +-- certificate | | +---u ks:local-or-keystore-end-entity-cert-with-key-\ grouping | +--:(raw-private-key) {raw-public-key-auth}? | | +-- raw-private-key | | +---u ks:local-or-keystore-asymmetric-key-grouping | +--:(psk) {psk-auth}? | +-- psk | +---u ks:local-or-keystore-symmetric-key-grouping +-- client-authentication! {client-auth-config-supported}? | +-- ca-certs! {x509-certificate-auth}? | | +---u ts:local-or-truststore-certs-grouping | +-- ee-certs! {x509-certificate-auth}? | | +---u ts:local-or-truststore-certs-grouping | +-- raw-public-keys! {raw-public-key-auth}? | | +---u ts:local-or-truststore-public-keys-grouping | +-- psks! {psk-auth}? +-- hello-params {tls-server-hello-params-config}? | +---u tlscmn:hello-params-grouping +-- keepalives {tls-server-keepalives}? +-- peer-allowed-to-send? empty +-- test-peer-aliveness! +-- max-wait? uint16 +-- max-attempts? uint8 Comments: * The "server-identity" node configures identity credentials, each of which is enabled by a "feature". Watsen & Wu Expires 9 January 2021 [Page 33] Internet-Draft Groupings for TLS Clients and Servers July 2020 * The "client-authentication" node, which is optionally configured (as client authentication MAY occur at a higher protocol layer), configures trust anchors for authenticating the TLS client, with each option enabled by a "feature" statement. * The "hello-params" node, which must be enabled by a feature, configures parameters for the TLS sessions established by this configuration. * The "keepalives" node, which must be enabled by a feature, configures a flag enabling the TLS client to test the aliveness of the TLS server, as well as a "presence" container for testing the aliveness of the TLSi client. The aliveness-tests occurs at the TLS protocol layer. * For the referenced grouping statement(s): - The "local-or-keystore-end-entity-cert-with-key-grouping" grouping is discussed in Section 2.1.3.6 of [I-D.ietf-netconf-keystore]. - The "local-or-keystore-asymmetric-key-grouping" grouping is discussed in Section 2.1.3.4 of [I-D.ietf-netconf-keystore]. - The "local-or-keystore-symmetric-key-grouping" grouping is discussed in Section 2.1.3.3 of [I-D.ietf-netconf-keystore]. - The "local-or-truststore-public-keys-grouping" grouping is discussed in Section 2.1.3.2 of [I-D.ietf-netconf-trust-anchors]. - The "local-or-truststore-certs-grouping" grouping is discussed in Section 2.1.3.1 of [I-D.ietf-netconf-trust-anchors]. - The "hello-params-grouping" grouping is discussed in Section 2.1.3.1 in this document. 4.1.3. Protocol-accessible Nodes The "ietf-tls-server" module does not contain any protocol-accessible nodes. 4.2. Example Usage This section presents two examples showing the "tls-server-grouping" grouping populated with some data. These examples are effectively the same except the first configures the server identity using a local key while the second uses a key configured in a keystore. Both examples are consistent with the examples presented in Section 2 of [I-D.ietf-netconf-trust-anchors] and Section 3.2 of [I-D.ietf-netconf-keystore]. Watsen & Wu Expires 9 January 2021 [Page 34] Internet-Draft Groupings for TLS Clients and Servers July 2020 The following configuration example uses local-definitions for the server identity and client authentication: =============== NOTE: '\' line wrapping per RFC 8792 ================ ct:subject-public-key-info-format base64encodedvalue== ct:rsa-private-key-format base64encodedvalue== base64encodedvalue== Identity Cert Issuer #1 Watsen & Wu Expires 9 January 2021 [Page 35] Internet-Draft Groupings for TLS Clients and Servers July 2020 base64encodedvalue== Identity Cert Issuer #2 base64encodedvalue== Application #1 base64encodedvalue== Application #2 base64encodedvalue== User A ct:subject-public-key-info-format base64encodedvalue== User B ct:subject-public-key-info-format base64encodedvalue== The following configuration example uses keystore-references for the server identity and truststore-references for client authentication: from the keystore: Watsen & Wu Expires 9 January 2021 [Page 36] Internet-Draft Groupings for TLS Clients and Servers July 2020 =============== NOTE: '\' line wrapping per RFC 8792 ================ rsa-asymmetric-key ex-rsa-cert trusted-client-ca-certs trusted-client-ee-certs Raw Public Keys for TLS Clients Watsen & Wu Expires 9 January 2021 [Page 37] Internet-Draft Groupings for TLS Clients and Servers July 2020 4.3. YANG Module This YANG module has a normative references to [RFC5246], [I-D.ietf-netconf-trust-anchors] and [I-D.ietf-netconf-keystore]. file "ietf-tls-server@2020-07-08.yang" module ietf-tls-server { yang-version 1.1; namespace "urn:ietf:params:xml:ns:yang:ietf-tls-server"; prefix tlss; import ietf-netconf-acm { prefix nacm; reference "RFC 8341: Network Configuration Access Control Model"; } import ietf-crypto-types { prefix ct; reference "RFC AAAA: YANG Data Types and Groupings for Cryptography"; } import ietf-truststore { prefix ts; reference "RFC BBBB: A YANG Data Model for a Truststore"; } import ietf-keystore { prefix ks; reference "RFC CCCC: A YANG Data Model for a Keystore"; } import ietf-tls-common { prefix tlscmn; revision-date 2020-07-08; // stable grouping definitions reference "RFC FFFF: YANG Groupings for TLS Clients and TLS Servers"; } organization "IETF NETCONF (Network Configuration) Working Group"; contact "WG Web: Watsen & Wu Expires 9 January 2021 [Page 38] Internet-Draft Groupings for TLS Clients and Servers July 2020 WG List: Author: Kent Watsen Author: Gary Wu "; description "This module defines reusable groupings for TLS servers that can be used as a basis for specific TLS server instances. Copyright (c) 2020 IETF Trust and the persons identified as authors of the code. All rights reserved. Redistribution and use in source and binary forms, with or without modification, is permitted pursuant to, and subject to the license terms contained in, the Simplified BSD License set forth in Section 4.c of the IETF Trust's Legal Provisions Relating to IETF Documents (https://trustee.ietf.org/license-info). This version of this YANG module is part of RFC FFFF (https://www.rfc-editor.org/info/rfcFFFF); see the RFC itself for full legal notices. The key words 'MUST', 'MUST NOT', 'REQUIRED', 'SHALL', 'SHALL NOT', 'SHOULD', 'SHOULD NOT', 'RECOMMENDED', 'NOT RECOMMENDED', 'MAY', and 'OPTIONAL' in this document are to be interpreted as described in BCP 14 (RFC 2119) (RFC 8174) when, and only when, they appear in all capitals, as shown here."; revision 2020-07-08 { description "Initial version"; reference "RFC FFFF: YANG Groupings for TLS Clients and TLS Servers"; } // Features feature tls-server-hello-params-config { description "TLS hello message parameters are configurable on a TLS server."; } feature tls-server-keepalives { description "Per socket TLS keepalive parameters are configurable for TLS servers on the server implementing this feature."; Watsen & Wu Expires 9 January 2021 [Page 39] Internet-Draft Groupings for TLS Clients and Servers July 2020 } feature client-auth-config-supported { description "Indicates that the configuration for how to authenticate clients can be configured herein, as opposed to in an application specific location. That is, to support the consuming data models that prefer to place client authentication with client definitions, rather then in a data model principally concerned with configuring the transport."; } feature x509-certificate-auth { description "Indicates that the server supports authenticating clients using X.509 certificates."; } feature raw-public-key-auth { description "Indicates that the server supports authenticating clients using ray public keys."; } feature psk-auth { description "Indicates that the server supports authenticating clients using PSKs (pre-shared or pairwise-symmetric keys)."; } // Groupings grouping tls-server-grouping { description "A reusable grouping for configuring a TLS server without any consideration for how underlying TCP sessions are established. Note that this grouping uses fairly typical descendent node names such that a stack of 'uses' statements will have name conflicts. It is intended that the consuming data model will resolve the issue (e.g., by wrapping the 'uses' statement in a container called 'tls-server-parameters'). This model purposely does not do this itself so as to provide maximum flexibility Watsen & Wu Expires 9 January 2021 [Page 40] Internet-Draft Groupings for TLS Clients and Servers July 2020 to consuming models."; container server-identity { nacm:default-deny-write; description "A locally-defined or referenced end-entity certificate, including any configured intermediate certificates, the TLS server will present when establishing a TLS connection in its Certificate message, as defined in Section 7.4.2 in RFC 5246."; reference "RFC 5246: The Transport Layer Security (TLS) Protocol Version 1.2 RFC CCCC: A YANG Data Model for a Keystore"; choice auth-type { mandatory true; description "A choice amongst authentication types."; case certificate { if-feature x509-certificate-auth; container certificate { description "Specifies the server identity using a certificate."; uses ks:local-or-keystore-end-entity-cert-with-key-grouping{ refine "local-or-keystore/local/local-definition" { must 'public-key-format' + ' = "ct:subject-public-key-info-format"'; } refine "local-or-keystore/keystore/keystore-reference" + "/asymmetric-key" { must 'deref(.)/../ks:public-key-format' + ' = "ct:subject-public-key-info-format"'; } } } } case raw-private-key { if-feature raw-public-key-auth; container raw-private-key { description "Specifies the server identity using a raw private key."; uses ks:local-or-keystore-asymmetric-key-grouping { refine "local-or-keystore/local/local-definition" { must 'public-key-format' + ' = "ct:subject-public-key-info-format"'; Watsen & Wu Expires 9 January 2021 [Page 41] Internet-Draft Groupings for TLS Clients and Servers July 2020 } refine "local-or-keystore/keystore/keystore-reference"{ must 'deref(.)/../ks:public-key-format' + ' = "ct:subject-public-key-info-format"'; } } } } case psk { if-feature psk-auth; container psk { description "Specifies the server identity using a PSK (pre-shared or pairwise-symmetric key). Note that, when the PSK is configured as a Keystore reference, the key's 'name' node MAY be used as the PSK's ID when used by the TLS protocol."; uses ks:local-or-keystore-symmetric-key-grouping { augment "local-or-keystore/local/local-definition" { if-feature "ks:local-definitions-supported"; description "An 'id' value for when the PSK is used by TLS."; leaf id { type string; // FIXME: is this the right type? description "The key id used in the TLS protocol for PSKs."; } } } } } } } // container server-identity container client-authentication { if-feature "client-auth-config-supported"; nacm:default-deny-write; must 'ca-certs or ee-certs or raw-public-keys or psks'; presence "Indicates that client authentication is supported (i.e., that the server will request clients send certificates). If not configured, the TLS server SHOULD NOT request the TLS clients provide authentication credentials."; description "Specifies how the TLS server can authenticate TLS clients. Any combination of credentials is additive and unordered. Note that no configuration is required for PSK (pre-shared Watsen & Wu Expires 9 January 2021 [Page 42] Internet-Draft Groupings for TLS Clients and Servers July 2020 or pairwise-symmetric key) based authentication as the key is necessarily the same as configured in the '../server- identity' node."; container ca-certs { if-feature "x509-certificate-auth"; presence "Indicates that the TLS server can authenticate TLS clients using configured certificate authority certificates."; description "A set of certificate authority (CA) certificates used by the TLS server to authenticate TLS client certificates. A client certificate is authenticated if it has a valid chain of trust to a configured CA certificate."; reference "RFC BBBB: A YANG Data Model for a Truststore"; uses ts:local-or-truststore-certs-grouping; } container ee-certs { // FIXME: plural too much? if-feature "x509-certificate-auth"; presence "Indicates that the TLS server can authenticate TLS clients using configured client certificates."; description "A set of client certificates (i.e., end entity certificates) used by the TLS server to authenticate certificates presented by TLS clients. A client certificate is authenticated if it is an exact match to a configured client certificate."; reference "RFC BBBB: A YANG Data Model for a Truststore"; uses ts:local-or-truststore-certs-grouping; } container raw-public-keys { if-feature "raw-public-key-auth"; presence "Indicates that the TLS server can authenticate TLS clients using raw public keys."; description "A set of raw public keys used by the TLS server to authenticate raw public keys presented by the TLS client. A raw public key is authenticated if it is an exact match to a configured raw public key."; reference "RFC BBBB: A YANG Data Model for a Truststore"; uses ts:local-or-truststore-public-keys-grouping { refine "local-or-truststore/local/local-definition" + "/public-key" { must 'public-key-format' Watsen & Wu Expires 9 January 2021 [Page 43] Internet-Draft Groupings for TLS Clients and Servers July 2020 + ' = "ct:subject-public-key-info-format"'; } refine "local-or-truststore/truststore" + "/truststore-reference" { must 'deref(.)/../*/ts:public-key-format' + ' = "ct:subject-public-key-info-format"'; } } } container psks { if-feature "psk-auth"; presence "Indicates that the TLS server can authenticate the TLS client using its PSK (pre-shared or pairwise-symmetric key)."; description "No configuration is required since the PSK value is the same as PSK value configured in the 'client-identity' node."; } } // container client-authentication container hello-params { nacm:default-deny-write; if-feature "tls-server-hello-params-config"; uses tlscmn:hello-params-grouping; description "Configurable parameters for the TLS hello message."; } // container hello-params container keepalives { nacm:default-deny-write; if-feature "tls-server-keepalives"; description "Configures the keepalive policy for the TLS server."; leaf peer-allowed-to-send { type empty; description "Indicates that the remote TLS client is allowed to send HeartbeatRequest messages, as defined by RFC 6520 to this TLS server."; reference "RFC 6520: Transport Layer Security (TLS) and Datagram Transport Layer Security (DTLS) Heartbeat Extension"; } container test-peer-aliveness { presence "Indicates that the TLS server proactively tests the Watsen & Wu Expires 9 January 2021 [Page 44] Internet-Draft Groupings for TLS Clients and Servers July 2020 aliveness of the remote TLS client."; description "Configures the keep-alive policy to proactively test the aliveness of the TLS client. An unresponsive TLS client is dropped after approximately max-wait * max-attempts seconds."; leaf max-wait { type uint16 { range "1..max"; } units "seconds"; default "30"; description "Sets the amount of time in seconds after which if no data has been received from the TLS client, a TLS-level message will be sent to test the aliveness of the TLS client."; } leaf max-attempts { type uint8; default "3"; description "Sets the maximum number of sequential keep-alive messages that can fail to obtain a response from the TLS client before assuming the TLS client is no longer alive."; } } } // container keepalives } // grouping tls-server-grouping } // module ietf-tls-server 5. Security Considerations 5.1. The "ietf-tls-common" YANG Module The "ietf-tls-common" YANG module defines "grouping" statements that are designed to be accessed via YANG based management protocols, such as NETCONF [RFC6241] and RESTCONF [RFC8040]. Both of these protocols have mandatory-to-implement secure transport layers (e.g., SSH, TLS) with mutual authentication. The NETCONF access control model (NACM) [RFC8341] provides the means to restrict access for particular users to a pre-configured subset of all available protocol operations and content. Watsen & Wu Expires 9 January 2021 [Page 45] Internet-Draft Groupings for TLS Clients and Servers July 2020 Since the module in this document only define groupings, these considerations are primarily for the designers of other modules that use these groupings. None of the readable data nodes defined in this YANG module are considered sensitive or vulnerable in network environments. The NACM "default-deny-all" extension has not been set for any data nodes defined in this module. None of the writable data nodes defined in this YANG module are considered sensitive or vulnerable in network environments. The NACM "default-deny-write" extension has not been set for any data nodes defined in this module. This module does not define any RPCs, actions, or notifications, and thus the security consideration for such is not provided here. 5.2. The "ietf-tls-client" YANG Module The "ietf-tls-client" YANG module defines "grouping" statements that are designed to be accessed via YANG based management protocols, such as NETCONF [RFC6241] and RESTCONF [RFC8040]. Both of these protocols have mandatory-to-implement secure transport layers (e.g., SSH, TLS) with mutual authentication. The NETCONF access control model (NACM) [RFC8341] provides the means to restrict access for particular users to a pre-configured subset of all available protocol operations and content. Since the module in this document only define groupings, these considerations are primarily for the designers of other modules that use these groupings. None of the readable data nodes defined in this YANG module are considered sensitive or vulnerable in network environments. The NACM "default-deny-all" extension has not been set for any data nodes defined in this module. | Please be aware that this module uses the "key" and "private- | key" nodes from the "ietf-crypto-types" module | [I-D.ietf-netconf-crypto-types], where said nodes have the NACM | extension "default-deny-all" set, thus preventing unrestricted | read-access to the cleartext key values. Watsen & Wu Expires 9 January 2021 [Page 46] Internet-Draft Groupings for TLS Clients and Servers July 2020 All of the writable data nodes defined by this module may be considered sensitive or vulnerable in some network environments. For instance, any modification to a key or reference to a key may dramatically alter the implemented security policy. For this reason, the NACM extension "default-deny-write" has been set for all data nodes defined in this module. This module does not define any RPCs, actions, or notifications, and thus the security consideration for such is not provided here. 5.3. The "ietf-tls-server" YANG Module The "ietf-tls-server" YANG module defines "grouping" statements that are designed to be accessed via YANG based management protocols, such as NETCONF [RFC6241] and RESTCONF [RFC8040]. Both of these protocols have mandatory-to-implement secure transport layers (e.g., SSH, TLS) with mutual authentication. The NETCONF access control model (NACM) [RFC8341] provides the means to restrict access for particular users to a pre-configured subset of all available protocol operations and content. Since the module in this document only define groupings, these considerations are primarily for the designers of other modules that use these groupings. None of the readable data nodes defined in this YANG module are considered sensitive or vulnerable in network environments. The NACM "default-deny-all" extension has not been set for any data nodes defined in this module. | Please be aware that this module uses the "key" and "private- | key" nodes from the "ietf-crypto-types" module | [I-D.ietf-netconf-crypto-types], where said nodes have the NACM | extension "default-deny-all" set, thus preventing unrestricted | read-access to the cleartext key values. All of the writable data nodes defined by this module may be considered sensitive or vulnerable in some network environments. For instance, any modification to a key or reference to a key may dramatically alter the implemented security policy. For this reason, the NACM extension "default-deny-write" has been set for all data nodes defined in this module. This module does not define any RPCs, actions, or notifications, and thus the security consideration for such is not provided here. Watsen & Wu Expires 9 January 2021 [Page 47] Internet-Draft Groupings for TLS Clients and Servers July 2020 6. IANA Considerations 6.1. The IETF XML Registry This document registers three URIs in the "ns" subregistry of the IETF XML Registry [RFC3688]. Following the format in [RFC3688], the following registrations are requested: URI: urn:ietf:params:xml:ns:yang:ietf-tls-common Registrant Contact: The NETCONF WG of the IETF. XML: N/A, the requested URI is an XML namespace. URI: urn:ietf:params:xml:ns:yang:ietf-tls-client Registrant Contact: The NETCONF WG of the IETF. XML: N/A, the requested URI is an XML namespace. URI: urn:ietf:params:xml:ns:yang:ietf-tls-server Registrant Contact: The NETCONF WG of the IETF. XML: N/A, the requested URI is an XML namespace. 6.2. The YANG Module Names Registry This document registers three YANG modules in the YANG Module Names registry [RFC6020]. Following the format in [RFC6020], the following registrations are requested: name: ietf-tls-common namespace: urn:ietf:params:xml:ns:yang:ietf-tls-common prefix: tlscmn reference: RFC FFFF name: ietf-tls-client namespace: urn:ietf:params:xml:ns:yang:ietf-tls-client prefix: tlsc reference: RFC FFFF name: ietf-tls-server namespace: urn:ietf:params:xml:ns:yang:ietf-tls-server prefix: tlss reference: RFC FFFF 7. References 7.1. Normative References [I-D.ietf-netconf-crypto-types] Watsen, K., "Common YANG Data Types for Cryptography", Work in Progress, Internet-Draft, draft-ietf-netconf- Watsen & Wu Expires 9 January 2021 [Page 48] Internet-Draft Groupings for TLS Clients and Servers July 2020 crypto-types-15, 20 May 2020, . [I-D.ietf-netconf-keystore] Watsen, K., "A YANG Data Model for a Keystore", Work in Progress, Internet-Draft, draft-ietf-netconf-keystore-17, 20 May 2020, . [I-D.ietf-netconf-trust-anchors] Watsen, K., "A YANG Data Model for a Truststore", Work in Progress, Internet-Draft, draft-ietf-netconf-trust- anchors-10, 20 May 2020, . [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, March 1997, . [RFC5288] Salowey, J., Choudhury, A., and D. McGrew, "AES Galois Counter Mode (GCM) Cipher Suites for TLS", RFC 5288, DOI 10.17487/RFC5288, August 2008, . [RFC5289] Rescorla, E., "TLS Elliptic Curve Cipher Suites with SHA- 256/384 and AES Galois Counter Mode (GCM)", RFC 5289, DOI 10.17487/RFC5289, August 2008, . [RFC6020] Bjorklund, M., Ed., "YANG - A Data Modeling Language for the Network Configuration Protocol (NETCONF)", RFC 6020, DOI 10.17487/RFC6020, October 2010, . [RFC7589] Badra, M., Luchuk, A., and J. Schoenwaelder, "Using the NETCONF Protocol over Transport Layer Security (TLS) with Mutual X.509 Authentication", RFC 7589, DOI 10.17487/RFC7589, June 2015, . [RFC7950] Bjorklund, M., Ed., "The YANG 1.1 Data Modeling Language", RFC 7950, DOI 10.17487/RFC7950, August 2016, . Watsen & Wu Expires 9 January 2021 [Page 49] Internet-Draft Groupings for TLS Clients and Servers July 2020 [RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, May 2017, . [RFC8341] Bierman, A. and M. Bjorklund, "Network Configuration Access Control Model", STD 91, RFC 8341, DOI 10.17487/RFC8341, March 2018, . [RFC8422] Nir, Y., Josefsson, S., and M. Pegourie-Gonnard, "Elliptic Curve Cryptography (ECC) Cipher Suites for Transport Layer Security (TLS) Versions 1.2 and Earlier", RFC 8422, DOI 10.17487/RFC8422, August 2018, . [RFC8446] Rescorla, E., "The Transport Layer Security (TLS) Protocol Version 1.3", RFC 8446, DOI 10.17487/RFC8446, August 2018, . 7.2. Informative References [I-D.ietf-netconf-http-client-server] Watsen, K., "YANG Groupings for HTTP Clients and HTTP Servers", Work in Progress, Internet-Draft, draft-ietf- netconf-http-client-server-03, 20 May 2020, . [I-D.ietf-netconf-netconf-client-server] Watsen, K., "NETCONF Client and Server Models", Work in Progress, Internet-Draft, draft-ietf-netconf-netconf- client-server-19, 20 May 2020, . [I-D.ietf-netconf-restconf-client-server] Watsen, K., "RESTCONF Client and Server Models", Work in Progress, Internet-Draft, draft-ietf-netconf-restconf- client-server-19, 20 May 2020, . [I-D.ietf-netconf-ssh-client-server] Watsen, K. and G. Wu, "YANG Groupings for SSH Clients and SSH Servers", Work in Progress, Internet-Draft, draft- ietf-netconf-ssh-client-server-19, 20 May 2020, . Watsen & Wu Expires 9 January 2021 [Page 50] Internet-Draft Groupings for TLS Clients and Servers July 2020 [I-D.ietf-netconf-tcp-client-server] Watsen, K. and M. Scharf, "YANG Groupings for TCP Clients and TCP Servers", Work in Progress, Internet-Draft, draft- ietf-netconf-tcp-client-server-06, 16 June 2020, . [I-D.ietf-netconf-tls-client-server] Watsen, K. and G. Wu, "YANG Groupings for TLS Clients and TLS Servers", Work in Progress, Internet-Draft, draft- ietf-netconf-tls-client-server-19, 20 May 2020, . [RFC2246] Dierks, T. and C. Allen, "The TLS Protocol Version 1.0", RFC 2246, DOI 10.17487/RFC2246, January 1999, . [RFC2818] Rescorla, E., "HTTP Over TLS", RFC 2818, DOI 10.17487/RFC2818, May 2000, . [RFC3688] Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688, DOI 10.17487/RFC3688, January 2004, . [RFC4346] Dierks, T. and E. Rescorla, "The Transport Layer Security (TLS) Protocol Version 1.1", RFC 4346, DOI 10.17487/RFC4346, April 2006, . [RFC5246] Dierks, T. and E. Rescorla, "The Transport Layer Security (TLS) Protocol Version 1.2", RFC 5246, DOI 10.17487/RFC5246, August 2008, . [RFC6241] Enns, R., Ed., Bjorklund, M., Ed., Schoenwaelder, J., Ed., and A. Bierman, Ed., "Network Configuration Protocol (NETCONF)", RFC 6241, DOI 10.17487/RFC6241, June 2011, . [RFC8040] Bierman, A., Bjorklund, M., and K. Watsen, "RESTCONF Protocol", RFC 8040, DOI 10.17487/RFC8040, January 2017, . [RFC8071] Watsen, K., "NETCONF Call Home and RESTCONF Call Home", RFC 8071, DOI 10.17487/RFC8071, February 2017, . Watsen & Wu Expires 9 January 2021 [Page 51] Internet-Draft Groupings for TLS Clients and Servers July 2020 [RFC8340] Bjorklund, M. and L. Berger, Ed., "YANG Tree Diagrams", BCP 215, RFC 8340, DOI 10.17487/RFC8340, March 2018, . [RFC8342] Bjorklund, M., Schoenwaelder, J., Shafer, P., Watsen, K., and R. Wilton, "Network Management Datastore Architecture (NMDA)", RFC 8342, DOI 10.17487/RFC8342, March 2018, . Appendix A. Change Log This section is to be removed before publishing as an RFC. A.1. 00 to 01 * Noted that '0.0.0.0' and '::' might have special meanings. * Renamed "keychain" to "keystore". A.2. 01 to 02 * Removed the groupings containing transport-level configuration. Now modules contain only the transport-independent groupings. * Filled in previously incomplete 'ietf-tls-client' module. * Added cipher suites for various algorithms into new 'ietf-tls- common' module. A.3. 02 to 03 * Added a 'must' statement to container 'server-auth' asserting that at least one of the various auth mechanisms must be specified. * Fixed description statement for leaf 'trusted-ca-certs'. A.4. 03 to 04 * Updated title to "YANG Groupings for TLS Clients and TLS Servers" * Updated leafref paths to point to new keystore path * Changed the YANG prefix for ietf-tls-common from 'tlscom' to 'tlscmn'. * Added TLS protocol verions 1.0 and 1.1. * Made author lists consistent Watsen & Wu Expires 9 January 2021 [Page 52] Internet-Draft Groupings for TLS Clients and Servers July 2020 * Now tree diagrams reference ietf-netmod-yang-tree-diagrams * Updated YANG to use typedefs around leafrefs to common keystore paths * Now inlines key and certificates (no longer a leafref to keystore) A.5. 04 to 05 * Merged changes from co-author. A.6. 05 to 06 * Updated to use trust anchors from trust-anchors draft (was keystore draft) * Now Uses new keystore grouping enabling asymmetric key to be either locally defined or a reference to the keystore. A.7. 06 to 07 * factored the tls-[client|server]-groupings into more reusable groupings. * added if-feature statements for the new "x509-certificates" feature defined in draft-ietf-netconf-trust-anchors. A.8. 07 to 08 * Added a number of compatibility matrices to Section 5 (thanks Frank!) * Clarified that any configured "cipher-suite" values need to be compatible with the configured private key. A.9. 08 to 09 * Updated examples to reflect update to groupings defined in the keystore draft. * Add TLS keepalives features and groupings. * Prefixed top-level TLS grouping nodes with 'tls-' and support mashups. * Updated copyright date, boilerplate template, affiliation, and folding algorithm. Watsen & Wu Expires 9 January 2021 [Page 53] Internet-Draft Groupings for TLS Clients and Servers July 2020 A.10. 09 to 10 * Reformatted the YANG modules. A.11. 10 to 11 * Collapsed all the inner groupings into the top-level grouping. * Added a top-level "demux container" inside the top-level grouping. * Added NACM statements and updated the Security Considerations section. * Added "presence" statements on the "keepalive" containers, as was needed to address a validation error that appeared after adding the "must" statements into the NETCONF/RESTCONF client/server modules. * Updated the boilerplate text in module-level "description" statement to match copyeditor convention. A.12. 11 to 12 * In server model, made 'client-authentication' a 'presence' node indicating that the server supports client authentication. * In the server model, added a 'required-or-optional' choice to 'client-authentication' to better support protocols such as RESTCONF. * In the server model, added a 'local-or-external' choice to 'client-authentication' to better support consuming data models that prefer to keep client auth with client definitions than in a model principally concerned with the "transport". * In both models, removed the "demux containers", floating the nacm:default-deny-write to each descendent node, and adding a note to model designers regarding the potential need to add their own demux containers. * Fixed a couple references (section 2 --> section 3) A.13. 12 to 13 * Updated to reflect changes in trust-anchors drafts (e.g., s/trust- anchors/truststore/g + s/pinned.//) Watsen & Wu Expires 9 January 2021 [Page 54] Internet-Draft Groupings for TLS Clients and Servers July 2020 A.14. 12 to 13 * Removed 'container' under 'client-identity' to match server model. * Updated examples to reflect change grouping in keystore module. A.15. 13 to 14 * Removed the "certificate" container from "client-identity" in the ietf-tls-client module. * Updated examples to reflect ietf-crypto-types change (e.g., identities --> enumerations) A.16. 14 to 15 * Updated "server-authentication" and "client-authentication" nodes from being a leaf of type "ts:certificates-ref" to a container that uses "ts:local-or-truststore-certs-grouping". A.17. 15 to 16 * Removed unnecessary if-feature statements in the -client and -server modules. * Cleaned up some description statements in the -client and -server modules. * Fixed a canonical ordering issue in ietf-tls-common detected by new pyang. A.18. 16 to 17 * Removed choice local-or-external by removing the 'external' case and flattening the 'local' case and adding a "client-auth-config- supported" feature. * Removed choice required-or-optional. * Updated examples to include the "*-key-format" nodes. * Augmented-in "must" expressions ensuring that locally-defined public-key-format are "ct:ssh-public-key-format" (must expr for ref'ed keys are TBD). Watsen & Wu Expires 9 January 2021 [Page 55] Internet-Draft Groupings for TLS Clients and Servers July 2020 A.19. 17 to 18 * Removed the unused "external-client-auth-supported" feature. * Made client-indentity optional, as there may be over-the-top auth instead. * Added augment to uses of local-or-keystore-symmetric-key-grouping for a psk "id" node. * Added missing presence container "psks" to ietf-tls-server's "client-authentication" container. * Updated examples to reflect new "bag" addition to truststore. * Removed feature-limited caseless 'case' statements to improve tree diagram rendering. * Refined truststore/keystore groupings to ensure the key formats "must" be particular values. * Switched to using truststore's new "public-key" bag (instead of separate "ssh-public-key" and "raw-public-key" bags. * Updated client/server examples to cover ALL cases (local/ref x cert/raw-key/psk). A.20. 18 to 19 * Updated the "keepalives" containers in part to address Michal Vasko's request to align with RFC 8071, and in part to better align to RFC 6520. * Removed algorithm-mapping tables from the "TLS Common Model" section * Removed the 'algorithm' node from the examples. * Renamed both "client-certs" and "server-certs" to "ee-certs" * Added a "Note to Reviewers" note to first page. A.21. 19 to 20 * Modified the 'must' expression in the "ietf-tls-client:server- authention" node to cover the "raw-public-keys" and "psks" nodes also. Watsen & Wu Expires 9 January 2021 [Page 56] Internet-Draft Groupings for TLS Clients and Servers July 2020 * Added a "must 'ca-certs or ee-certs or raw-public-keys or psks'" statement to the ietf-tls-server:client-authentication" node. * Added "mandatory true" to "choice auth-type" and a "presence" statement to its ancestor. * Expanded "Data Model Overview section(s) [remove "wall" of tree diagrams]. * Moved the "ietf-ssh-common" module section to proceed the other two module sections. * Updated the Security Considerations section. Acknowledgements The authors would like to thank for following for lively discussions on list and in the halls (ordered by last name): Andy Bierman, Martin Bjorklund, Benoit Claise, Mehmet Ersue, Balazs Kovacs, Radek Krejci, David Lamparter, Ladislav Lhotka, Alan Luchuk, Tom Petch, Juergen Schoenwaelder, Phil Shafer, Sean Turner, Michal Vasko, Bert Wijnen, and Liang Xia. Authors' Addresses Kent Watsen Watsen Networks Email: kent+ietf@watsen.net Gary Wu Cisco Systems Email: garywu@cisco.com Watsen & Wu Expires 9 January 2021 [Page 57]